please... logic states that choice alone hurts retention rates in an environment where actors are struggling with differentiation. this is not some fantasy-creature made up by android fanboys, its common sense.
Actually, the logic is the exact same when it comes to viewing Android as a whole. The consumer option, in many ways, is more of Android vs. iOS/iphone (as ios is only available on iphones its pretty much interchangable).
Choice is a key enabler for Androids market-share as such, and choice is key reason for poor retention rates. One is the flip-side of the other. The unifying element: differentiation, or, rather, lack of there-of (enables choice, delimits ability for retention).
...this is also why a common strategy under shared-platform competition scenarios is to increase differentiation, as to allow consumer lock-in. once again, common sense. Here examples are plentiful, ranging from vendor-specific applications, UI-overlays and value-adding services.